If you need to test and verify port accessibility for ConfigMgr clients, there’s now a tool available from Trevor Jones.
This tool is for TCP port testing on SCCM client systems. It checks the local ports required by the SCCM client as well as connectivity to management point, distribution point and sofware update point servers. In addition, there is a custom port tester for testing any inbound or outbound port to any destination.
Use the tool to verify that the client can communicate on the required ports for SCCM. The default ports can be edited in the case that non-default port numbers are in use, or additional ports are required.
It will only test TCP ports, not UDP.
Download from TechNet: ConfigMgr Client TCP Port Tester
For full details see, Trevor’s blog: https://smsagent.blog/2019/03/07/configmgr-client-tcp-port-tester/